Ethernet and IP communications have become the most popular means of computer communications, in part due to the simplicity and scalability of connectionless, packet-oriented communications over a statistically multiplexed network. As Ethernet moves to 10 Gbps speeds and beyond, it would be useful to utilize this commodity technology in specialized high performance parallel computing environments where traditionally specialized interconnect fabrics have been deployed. The interconnect fabrics commonly used in the high performance parallel computing environments are designed for Message Passing Interface (MPI) applications. These interconnect fabrics are focused on connection oriented, low latency and high-bandwidth communications, but are often complex and expensive. Using commodity Ethernet packet switches instead of specialized interconnection fabrics can lower both the cost and the complexity of the parallel computing systems. However, current Ethernet packet switches suffer from excessive switch latency. If these packet switches are deployed in lieu of MPI-based interconnect fabrics in parallel computing systems, data transmission could result in system bottlenecks and increased response times.
In addition, there is a trend towards multiplexing a variety of different traffic types (e.g., voice, video and data), each potentially with different service requirements, onto the same network fabric. In all of these situations, low latency, yet policy-rich forwarding based upon flow classification would be useful. Providing these rich forwarding features without negatively impacting the switch latency puts extreme pressure on the classification process of a network switch to be fast and reliable.